The dangerous cold has some school districts canceling classes Tuesday and others delaying start times by two hours. Duluth, Ely, Esko and Hermantown are among the districts telling students to stay home.

Forecasters say Monday's low of 10 below zero, in Duluth, was the coldest temperature recorded there since February 2007.

The extreme cold means a busy day for AAA Minneapolis. Spokesman Matt Hehl says they handled about 900 calls from motorists Monday — about twice the normal volume.